Effect of Pb-Te-Si-O glasses on Ag thick-film contact in crystalline silicon solar cells

Abstract

Abstract In the paper, the influences of Pb-Te-Si-O (PTSO) glasses on Ag thick-film contact in crystalline silicon solar cells were investigated. Thermal properties of PTSO glasses and the dissolution process of Ag were studied. The formation of a new low-softening-temperature glassy-phase, induced by the crystallization of PTSO-1 glass, accelerated the dissolution of Ag at lower temperature. When silver paste was sintered, high-viscosity PTS-1 glass could flow to the surface of the cell and etch SiNx ARC layer at relative high temperature and the time for etching through SiNx ARC layer was shorter. Viscosity-temperature properties of PTSO glass has played a great role in the microstructures of contact finger and Ag/Si interface and have a great effect on the quality of Ag/Si contact and electrical properties of cells by affecting the sintering process of Ag, the etching behavior of interfacial glass with SiNx and Si, and the size and size distribution of Ag crystallites grown into the Si emitter at the position of inverted-pyramid etching pits.